Since the emergence of Boko Haram in Northern Nigeria, a startling trajectory of terrorism manifested itself in catastrophic death and destruction including massive population displacement that left millions of people in need of humanitarian assistance in the worst affected states of Adamawa, Bornu, and Yobe. The preponderance of Boko Haram’s tactical violence and the culminating impact on population displacement underscores the limited capacity of the state to protect its citizens from security threats arising from within its sovereign territoriality. This chapter contends that neglecting the victims of terror-induced displacement not only constitutes a breach of human rights but also a national security threat. The author draw insights from theories of sovereignty and domestic responsibility to examine the question: Who has the responsibility to defend victims of terror in Northeast Nigeria? This chapter argues that, in the context of terrorism in Northeast Nigeria, the state has lost its monopoly over the means of violence and its capacity to protect victims of terror and may need to rethink its human rights responsibility. In this context, this chapter introduces the “responsibility to defend” (R2D) as a new concept with far-reaching theoretical and practical implications as it pertains to the human rights of IDPs.